HVAC Overhaul
Materials:
1/4 inch thick foam (used 1/2)
Adhesive (used general 3M adhesive)
Silicone
7/16, 5/16 sockets/wrenches
Extensions
Flathead
Pliers
Crescent wrenches
Currently restoring my interior, hot Texas months are coming and while the dash is out I decided to boost my cold air. If any of you have the dash out or plan to, I would 1000% recommend going into your HVAC tubes and boxes and clean them with soap and water. So much gunk piles up in there over the years. If you're replacing something down there, it wouldn't be a bad idea to replace the evaporator core and blower motor. Removing evaporator core makes removing the box miles easier. Tender love and care is definitely neglected in this area and your lungs would appreciate.
Pulling the dash wasn't that hard there was a guide online but I'll see how reinstalling goes once I'm at that point.
Under the assumption the dash is off.
To start off, remove the lines from the heater core, and disconnect the lines going to the evaporator core. The main HVAC assembly is removed by taking off the nuts off two bolts found in the engine bay penetrating through the firewall.. The bolts mentioned also hold the bracket for the accumulator. Remove using 5/16 deep sockets and loosen the screw holding the accumulator to the bracket 5/16 socket to remove the bracket. Get the accumulator out of the way and use the 5/16 deep sockets again to remove the nipple bolts holding the bolts to the firewall. Drink some beer.
Remove the four bolts holding the assembly from inside the cabin using 7/16 socket, an extension may help for the lowest one.
With the box out, easily access to the evaporator core blower motor, resistor, heater core and the diverters.
Blower motor:
The blower motor on my application worked fine, but I found the aftermarket blower a bit more powerful. Only 4 5/16 screws hold the blower motor to the box and easily pulls out. New blower motor I bought didn't come with the bladed wheel, so I had to take it off of the old one. Using a screw driver to push down on the center stud that holds the wheel to the motor and pulling up from under was the best way that I found since I didn't want to break the plastic, but I'm clumsy and dropped it so I accidentally broke a blade. A broken blade like mine won't cause vibrations and noise. To remove the case from the rest of the assembly, there is one side screw and one bolt on the underside.
*this image already has newly placed foam to seal the junction*
*there is no need to crack open the case that holds the blower motor, if replacing the foam for the diverted you can manage fine without opening*
Cracked open the case about 9 5/16 screws and 6 clips, depending how lazy your ford mechanic was, to open it. This is the case that holds the evap and heat core and opened relatively easy. Seemed like the sealant that was used to keep it sealed was old and wasn't very adhesivyyy. Further investigation led to seeing this nest of debris invading my evaporator core. Probably why I wasn't getting great air flow.
Heater core seemed in decent shape but I decided to replace it anyways. Side by side comparison of evaporator core and heater core.
Before installing the new cores, one thing I did notice is that the foam on the temperature control diverters was very crumbly and degrades into fine dust particulars. Scraped it off, went to Walmart and bought some foam and cut it into the proper shapes, and glued it onto the diverters using 3M general spray adhesive. It would save time if you can conceive 1/4" thick foam but thickness didn't matter as long as it's no thicker than 1/2" thick. For the temperature (heater core/evaporator core) diverter 1/2" thickeners worked fine, but I found it easier to take the diverter out of the box to work on. The rod that holds it is removed by popping it out of the center clip on the diverted flap.
With the diverter that opens to the cabin on the passenger side of the vehicle, the foam I bought was too thick. 1/4" foam thickness is needed or the diverter wouldn't seal correctly so I jerry rigged the foam I had and cut it in "half" When cutting out the shapes, I let the foam extend off of the diverted just a tad bit, cutting it to the exact shape of the diverters will not create a great seals.
Cores:
If you're just removing the heater core, loosen the accumulator bracket, don't disconnect the ac lines. Regardless; there are 5 5/16 screws the hold the door to the heater core box.
If you order the heater core from lmr, they provide foam to wrap around the heater core but not the evaporator core. All you need to wrap the heater core is foam 2"x24" and foam 2"x36" to wrap the evaporator core. In the pictures I wrapped the foam around the cores exactly how they are on from factory. Once again, the general adhesion actually provided great bond, I'd generously spray the foam then apply on the cores.
Furthermore, since foam is the name of the game, might as well replace the foam at the junction between the blower box and the core box. I did not replace the foam that seals the junction between the blower box and engine bay, it's black but it was in good condition.
Since everything is right in front of you it's not a bad idea to make sure air flow is prime. I used silicone to seal the box. I used just enough to fill the little indention. I also had a crack near the firewall bolts so I just covered it with silicone.
*make sure your diverters function before sealing the box*
Reinstall reverse procedure. I'll update when I make more progress. Apparently there isn't a cabin filter :Oo
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More importantly nothing needs to be disconnected to do this so its super simple. Heater core access is 4 screws as noted of course
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